The present invention relates to audio mixers and more particularly to a technique for controlling input channel settings corresponding to types of input sources.
The “5.1-channel surround” is a configuration of an audio signal output system which is configured to achieve a surround environment rich in presence by reproducing audio signals of six channels (surround signals), for which are set sound characteristics (sound image localization etc.) corresponding to a six-channel surround environment, using six speakers corresponding to the individual channels. The surround signals supply six types of audio signals corresponding to different types of output destinations, i.e. left front (L), right front (R), center front (C), left rear (Ls) and right rear (Rs) as viewed from a listener of the signals and low-pitched sound outputting subwoofer (LFE (Low Frequency Effects)).
Namely, in the 5.1-channel surround configuration, six input sources are handled together as one set, and a mutual relationship among the six input sources is set in advance regarding parameters of sound characteristics, such as sound volume level and sound image localization, in order to reproduce a predetermined surround environment.
In the conventionally-known audio mixers, when audio signals of a set of six input sources for the 5.1-channel surround are to be input, input channels are mapped or allocated to the six input sources in a one-to-one relationship so that one surround signal is input to each of the six input channels. Then, each of the input channels is connected to six mixing buses, processing, such as adjustment of levels of signals input to the mixing buses, is performed for each of the input channels and the resultant audio signals of these six mixing buses are output to six speakers corresponding to the mixing buses, to thereby reproduce the 5.1-channel surround audio signals in a surround environment, or recorded in a 5.1-channel surround configuration.
Namely, the conventionally-known audio mixers, where a plurality of input sources, whose mutual relationship was set in advance, are allocated to the different input channels, can only handle the input sources as mutually independent and mutually unrelated input sources. Thus, a human operator has to adjust parameters of each of the input channels separately from the other input channels while paying attention to the relationship among the input sources.
Further, whereas a plurality of signals to be reproduced in a surround environment should be output to a plurality of output destinations on a channel-by-channel basis, the conventionally-known audio mixers requires a human operator to also manually perform various operation, such as setting of connections of each input channel to mixing buses and adjustment of output levels, to the mixing buses, of each input channel, while paying attention to the relationship among the input sources.
Some of the conventionally-known audio mixers are equipped with a surround function (mode) for outputting audio signals to a plurality of output destinations that constitute a surround environment, such as 5.1-channel surround. However, this surround function is merely intended to realize a surround environment by outputting an audio signal of one input channel to a predetermined plurality of surround buses (see page 143 etc., “PM5D/PM5D-RH V2, DSP5D Owner's Manual”, [online], Yamaha, Internet <URL: http://www2.yamaha.co.jp/manual/pdf/pa/english/mixers/pm5dv2_en_om_g0.pdf>) (hereinafter referred to as “relevant non-patent literature”).
Further, some of the conventionally-known audio mixers are equipped with a function called “stereo pair setting” for handling a plurality of input channels together as a set. This stereo pair setting function is intended to set two input channels as a stereo pair to thereby achieve a ganged (or interlocked) relationship between parameters of the two input channels set as the stereo pair ((see page 53 of the above-identified non-patent literature).
However, with the conventionally-known audio mixers, a setting for handling audio signals of a plurality of channels, originally created for a surround purpose, cannot be made with the input channels of the mixer. Thus, in a case where audio signals of a plurality of channels are supplied from a plurality of input sources that are to be handled as a set as in the 5.1-channel surround or the like, cumbersome and time-consuming operation has been necessary for adjusting parameters of each of the input channels while paying attention to the relationship among the input sources and for outputting (e.g., surround-reproducing) the audio signals of the plurality of channels, which are to be handled as a set, as audio signals of a plurality of channels having a predetermined relationship thereamong.